I use it as a suicide lead with Spikes, Destiny Bond, Taunt, and Ice Shard with Focus Sash as the item; Jolly is the nature with a 252/252 spread. Ice Shard may seem odd, but it can actually destroy Ninjask and Aerodactyl leads if your damage can roll high enough. Also, it adds extra utility against Dragons later in the match if Froslass comes through the leading unscathed. I find that Ice Beam/Shadow Ball barely ever gets used in the lead spot anyway, since I usually just switch out of Azelf leads since they'll easily Taunt and kill you, and it doesn't really prevent Metagross or Machamp from doing their jobs (though you still get at least 1 layer up on them).
One piece of advice if you're going to use Froslass though; do NOT use it as your only Ghost. It's a horrible idea since Froslass is a suicide lead. Have a Rotom-A, Spiritomb, or Dusknoir on your team as well. I'd recommend Rotom-A since its STABs will hurt a lot with max Special Attack and entry hazards.